JPH09132997A - High rigid coupling of segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a rotational spring constant of a coupling part, decrease the sectional force applied to a segment and to give a reinforcement effect of the coupling part by increasing the rigidity of the coupling part while the original function of a washer is fulfilled. SOLUTION: A coupling for connecting segments is adapted to pass a bolt 3 through coupling plates 5, 5 provided on segment pieces 10, 10 to be connected to each other by using a bolt box 8 and fasten a nut 4 to connect the segments to each other. High rigid washers having a larger thickness (t) and a larger outside diameter (d) are interposed between the head 3' of the bolt 3 and the coupling plate 5 and between the nut 4 and the coupling plate 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high rigidity joint of a segment for constructing a shield tunnel.

[0002]

2. Description of the Related Art FIG. 11 is a perspective view showing an outline of a shield tunnel to which the present invention is directed, and FIG. 12 is a development view taken along line EE of FIG.

In the shield tunnel 13 shown in these figures, after excavating a tunnel, the segment pieces 10, 10 adjacent to each other in the tunnel axis direction and the tunnel axis orthogonal direction are connected to each other by the segment joint 11 and the ring joint 12. Connect them in a ring shape to build a segment.

Next, FIG. 13 is an enlarged view showing a prior art of a segment joint and a segment joint as a ring joint, and FIG. 14 is a sectional view taken along the line FF of FIG.

The conventional segment joints shown in FIGS. 13 and 14 are the segment pieces 1 to be joined together.
Joint plates 5 and 5 and bolt boxes 8 and 8 are provided on the mating surfaces of 0 and 10.

A bracket 6 is attached to each joint plate 5 with a span L therebetween. An anchor member 7 is attached to each bracket 6. Then, the joint plate 5 is fixed to the segment piece 10 via the anchor member 7 and the bracket 6.

The segment pieces 1 to be connected to each other
The joint plates 5 and 5 provided in Nos. 0 and 10 are provided with bolt through holes, and the bolt through holes sandwich the washer 2 between one joint plate 5 and the head 3 ′ of the bolt 3. The shaft portion of the bolt 3 is inserted, the washer 2 is fitted to the shaft portion of the bolt 3, and the nut 4 is attached. The washer 2 is sandwiched between the other joint plate 5 and the nut 4, and the nut 4 is tightened. The plates 5 and 5 are fastened with bolts and nuts 3 and 4, and the segment piece 1
0 and 10 are connected.

Reference numeral 14 in FIG. 14 is a haunch portion.

[0009]

By the way, in the above-mentioned conventional segment joint, it is interposed between the head 3'of the bolt 3 and one joint plate 5 and between the other joint plate 5 and the nut 4. The washer 2 has a donut shape formed with an outer diameter slightly larger than the head 3 ′ of the bolt 3 and the nut 4, and has an inner diameter slightly larger than the shaft diameter of the bolt 3, and is relatively large. The thin one is used.

As a result, the washer 2 reduces friction,
Although it has functions of preventing rattling at the time of tightening and preventing it from biting into the joint plate 5, it is formed only in the size and thickness necessary to satisfy those functions.

Therefore, in the segment joint using the washer 2, when the beam-spring model is examined, the effective width of the joint plate 5 is not so wide as compared with the case where the washer is not used, and the joint portion There is no effect on high rigidity. As a result, the rotating spring constant of the joint portion is small, the sectional force acting on the segment is large, and the joint portion has no reinforcing effect.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make use of the original function of the washer and to increase the rigidity of the joint to thereby increase the rotational spring constant of the joint. The object is to provide a high-rigidity joint for a segment that can increase the strength of the joint, reduce the cross-sectional force acting on the segumet, and impart a reinforcing effect to the joint.

[0013]

In order to achieve the above object, in the present invention, the segment pieces 1 to be joined to each other.
In the joint for segment coupling, in which the bolt 3 is passed through the joint plates 5 and 5 provided on the rails 0 and 10 and the nut 4 is tightened to be coupled, the head 3'of the bolt 3 and The bolt 3 is provided between the joint plates 5 and between the nut 4 and the joint plate 5.
Where the shaft diameter of is a, the thickness t of the high-rigidity washer is 0.4a or a size within a range that does not hinder tightening of the bolts, nuts 3 and 4 in the bolt box 8.
The high-rigidity washer has an outer diameter d of 2.5a or a size that can be accommodated in the bolt box 8.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing a first embodiment of the present invention,
FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 9 is a conceptual diagram of axial force transmission in the first embodiment of the present invention, and FIG. 10 is a comparison of the present invention and the prior art with respect to the bending moment acting on the segment piece. It is the bending moment figure shown by.

In the first embodiment shown in FIGS. 1 and 2, between the head 3'of the bolt 3 and the one joint plate 5,
A high-rigidity washer 1 is interposed between the other joint plate 5 and the nut 4.

The high-rigidity washer 1 is a ductile, S
It is formed of a material such as 45C, SM, and SS in a donut shape having a large thickness t and an outer diameter d. As shown in FIG. 9, the thickness t of the high-rigidity washer 1 is 0.4a or the bolt box 8 when the shaft diameter of the bolt 3 is a.
It is formed in a size that does not come to support the tightening of the bolts, nuts 3 and 4 therein. Further, the outer diameter d of the high-rigidity washer 1 is formed to be 2.5a or a size within a range that can be accommodated in the bolt box 8. When the thickness t of the high-rigidity washer 1 is less than 0.4a and the outer diameter d of the washer 1 is less than 2.5a, the desired reinforcing effect on the joint portion cannot always be obtained. It is desirable that the thickness is about twice as large as that of the conventional washer in order to achieve high rigidity performance, and the amount of protrusion c from the nut is not less than the thickness.

Reference numeral 9 in FIG. 2 is a haunch portion.

Generally, the strength required for a segment joint is specified so that the allowable moment of the segment joint is 60% or more of the resistance moment of the segment itself according to the design concept of "standard segment for shield construction". Has been done. This idea is effective when the conventional calculation method is used in which the segment ring has uniform rigidity. However, for large-diameter cross-sections and irregular cross-sections such as rectangles and ellipses, the spring of the joint is considered. -Because the spring model needs to be examined, the above provisions alone are not sufficient.

In the calculation method based on the beam-spring model, the effect of the zigzag set of joints is made more realistic by designing in consideration of the rotary spring of the inter-segment joint 11 and the shear spring constant of the inter-ring joint 12. Can be expressed as

In the examination by the beam-spring model, the larger the rotational spring constant of the inter-segment joint 11 is, the closer the rigidity is to uniformity, and the smaller the cross-sectional force generated in the segment piece 10 is.

The rotational spring constant is obtained by dividing the moment acting on the joint by the rotational angle, and its unit is t · m.
It is represented by / rad. The rotation spring constant is determined by the structure of the joint, and the thickness of the joint plate 5 and the span L
Greatly influenced by The thickness t of the joint plate 5 is large,
The shorter the span L, the larger the rotation spring constant.

Here, the span L of the joint plate 5 is
The distance between the insides of the brackets 6 that fix the joint plate 5 at both ends thereof. The bracket 6 is fixed to the anchor material 7 and embedded in the concrete of the segment piece 10. It is desirable that the span L of the joint plate 5 be as short as possible within a range where bolting work can be performed.

As described above, by mounting the high-rigidity washer 1 between the head portion 3'of the bolt 3 and the one joint plate 5 and between the other joint plate 5 and the nut 4, each joint plate 5 is inserted. The effective width of is widened. For this reason,
Beams where the model of the joint is considered as beams with both ends fixed or lattice beams −
When studied in the spring model, the deformation of the joint plate 5 can be reduced. As a result, the rotation angle of the joint portion decreases, and the rotation spring constant can be increased.

The high-rigidity washer 1 includes a joint plate 5
The effect is greater as the size becomes sufficiently close to the end in the span L direction, that is, the outer diameter d is increased as much as possible. Further, the high-rigidity washer 1 needs to have a thickness t sufficient to transmit the axial force acting from the bolt 3 and the nut 4 to the joint plate 5.

As shown in FIG. 9, the line expanded from the head 3'of the bolt 3 and the end of the nut 4 on the contact surface between the joint plate 5 and the high-rigidity washer 1 at an angle of 45.degree. Since it can be considered that the bolt axial force is sufficiently transmitted within the range intersecting with 5, the length of the high-rigidity washer 1 is about the same as the length of the head 3'of the bolt 3 and the outer circumference of the nut 4, A thickness close to that is required.

As described above, the thickness of the segment piece 10 can be reduced by increasing the joint rigidity. Alternatively, the amount of rebar (steel material) used in the segment piece 10 can be reduced. Therefore, by reducing the thickness of the segment piece 10, the concrete material can be reduced and the cost can be reduced, and the cross section of the shield tunnel 13 can be reduced, so that the excavated soil can be reduced and the excavated soil can be removed. The amount of soil treatment is also reduced, so environmental protection can be achieved. For example, if the segment thickness is 250 mm and the bolt diameter is M2
4, joint plate 5 thickness s = 22 mm, span L = 1
At 10 mm, if a high-rigidity washer 1 with an outer diameter of 70 mm and a thickness of 12 mm is used instead of the washer 2 with an outer diameter of 44 mm and a thickness of 4.5 mm, the rotational spring constant is 1.55 times for both positive and negative bending. become. This high-rigidity washer 1
Is used for a rectangular cross-section segment having an outer diameter of 4200 mm in lateral diameter × 3800 mm in longitudinal diameter × 250 mm in thickness, FIG.
As you can see, the maximum bending moment is 6.4tf
It is possible to reduce the thickness of the segment piece 10 to 225 mm by reducing it from m to 5.7 tf · m by about 10%.

Furthermore, by using the high-rigidity washer 1, even if the thickness s of the joint plate 5 is reduced, the joint rigidity with the same degree of rotary spring constant can be obtained.

In general, of all the shield lines, only when the condition is changed, such as when there is a large amount of soil cover or when it is necessary to cover a large amount of rebar in a salt-containing section, only the position where the condition is the most severe It is very uneconomical to determine the shield cross section and the shape of the joint with. In such a case, it is not necessary to increase the thickness of the segment piece 10 by reinforcing the joint using the high-rigidity washer 1 in a section where the conditions are severe, and it is possible to reduce an increase in the excavated cross section and the like.

Next, FIG. 3 is a side view showing a second embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB of FIG.

In the second embodiment shown in FIGS. 3 and 4, the high-rigidity washer 14 is integrally formed with a disk-shaped portion 14a having a bolt through hole and a conical portion 14b having a bolt through hole. It is formed in a shape.

The high-rigidity washer 14 used in the second embodiment has a head portion 3'of the bolt 3 and an end portion of the nut 4 4 as shown in the axial force transmission conceptual diagram of FIG.
If the line expanded at an angle of 5 ° is within the range where it intersects with the joint plate 5, it is considered that the bolt axial force is sufficiently transmitted. Therefore, it can be said that the extra shape is removed and the shape is rational.

Other configurations and operations of the second embodiment are the same as those of the first embodiment.

Next, FIG. 5 is a side view showing a third embodiment of the present invention, and FIG. 6 is a sectional view taken along the line CC of FIG.

In the third embodiment shown in FIGS. 5 and 6, the high-rigidity washer 15 is formed in a quadrangle having bolt through holes.

The high-rigidity washer 15 may be a pentagon or a polygon such as a hexagon.

The other structure and operation of the third embodiment are the same as those of the first embodiment.

Next, FIG. 7 is a side view showing a fourth embodiment of the present invention, and FIG. 8 is a sectional view taken along the line DD of FIG.

In the fourth embodiment shown in FIGS. 7 and 8, the high-rigidity washer 16 is a stack of two washers 16a,
16b. The one washer 16
a is formed to have a large thickness and a large diameter.
Located on the side. The other washer 16b is thicker and has a smaller diameter than the washer 16a, and is arranged on the head 3'side and the nut 4 side of the bolt 3.

Further, in the fourth embodiment, the high-rigidity washer 16 may be formed by stacking three or more sheets.

The operation of the fourth embodiment is the same as that of the second embodiment, and the other constructions and operations are the same as those of the first embodiment.

[0042]

As described above, according to the first aspect of the present invention,
According to the invention described, between the head 3 ′ of the bolt 3 inserted in the joint plates 5 and 5 provided on the segment pieces 10 to be connected to each other and the plate 5, and the nut fitted to the bolt 3. 4 and the joint plate 5, a high-rigidity washer having a large thickness t and an outer diameter d is interposed, so that the original function of the washer is utilized and the rigidity of the joint is increased. Therefore, the rotational spring constant of the joint portion can be increased, and therefore, the sectional force acting on the segment can be reduced, and the effect of reinforcing the joint portion can be exerted. Along with this, the thickness of the segment piece 10 can be reduced, and as a result, there is an effect that the cost can be reduced due to the reduction of the concrete material, and the cross section of the shield tunnel can be reduced. As a result of reducing the amount of processing, there is an effect that can contribute to environmental conservation. Furthermore, there is an effect that the amount of reinforcing bars used in the segment piece 10 can be reduced, or that the joint plate 5 can be thinned without changing the rotary spring constant.

When the shaft diameter of the bolt 3 is a, the thickness t of the high-rigidity washer is 0.4a or within a range that does not hinder tightening of the bolts, nuts 3 and 4 in the bolt box 8. The outer diameter d of the high rigidity washer is set to 2.
Since it is formed in a size that can be accommodated within the bolt box 8 or 5a, the original function of the washer can be utilized and the rigidity of the joint portion can be more surely increased to increase the rotational spring constant of the joint portion. There is an effect that the cross-section force acting on the segumet can be increased and the reinforcing effect of the joint part can be imparted.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a side view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a side view showing a third embodiment of the present invention.

FIG. 6 is a sectional view taken along line CC of FIG. 5;

FIG. 7 is a side view showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view taken along line DD of FIG. 7;

FIG. 9 is a conceptual diagram of axial force transmission in the first embodiment of the present invention.

FIG. 10 is a bending moment diagram showing a comparison between the present invention and the prior art regarding a bending moment acting on a segment piece.

FIG. 11 is a perspective view showing an outline of a shield tunnel targeted by the present invention.

12 is a development view taken along line EE in FIG.

FIG. 13 is an enlarged view showing a prior art of a segment joint as a segment joint and a ring joint.

FIG. 14 is a sectional view taken along line FF of FIG. 13;

[Explanation of symbols]

 1 High-rigidity washers 3 Bolts 3'Bolt heads 4 Nuts 5 Joint plates 6 Brackets 7 Anchors 8 Bolt boxes 10 Segment pieces 11 Inter-segment joints 12 Ring inter-joints 13 Shield tunnels 14, 15, 16 High-rigidity washers a For bolts Shaft diameter d Outer diameter of high rigidity washer t Thickness of high rigidity washer

Claims (1)

[Claims] 1. A segment piece 1 to be joined together.
A joint for segment coupling in which the bolt 3 is inserted into the joint plates 5 and 5 provided on the rails 0 and 10 and the nut 4 is tightened to be joined. When the shaft diameter of the bolt 3 is a between the joint plates 5 and between the nut 4 and the joint plate 5, the thickness t of the high-rigidity washer is 0.4a or the bolt is inside the bolt box 8. The outer diameter d of the high-rigidity washer is 2.5a or a size that can be accommodated in the bolt box 8 within a range that does not hinder tightening of the nuts 3 and 4. High-rigidity joint for segment.